More specifically the invention relates to a fan unit of the type comprising: a plate-like support structure or shroud which has a main opening defining a passage for an air flow for ventilation of the exchanger; and an electric fan including an electric drive motor fixed to the support structure or shroud in the region of the main opening, and an impeller with blades arranged inside the main opening and connected to the drive motor. A spray protection screen is associated with the side of the motor remote from the impeller and is fixed to the support structure in such a way that, during use, it is substantially vertical and defines at the bottom at least one inlet opening suitable for being passed through, during operation, by an air flow for cooling the motor.
In fan units of this type manufactured hitherto it is possible that, during operation, in the event of rain, a stream of water may flow along the outer surface of the spray protection screen and be sucked up so that it passes over the electric motor driving the fan impeller. This, of course, is undesirable.
Hence there is a need for an improved fan unit of the type specified above which is able to overcome the abovementioned drawback of the fan units according to the prior art.